[Lathe] 1919 Lot 5 Dalton Lathe - Bearing Shim Question

[Glenn Brooks]

just finishing up a restoration of my lot 5 Dalton lathe. It's in very good condition overall, but has some slop in the headstock bearings. In taking it apart, I think I lost one of the shims from under the bearing cap at the chuck, hence the spindle 'clinks' a bit when I pull it vertically up and down. The bearings are split, so one upper and one lower front and back.

I will be putting a dial indicator on the spindle to measure movement, probably tomorrow.

So it brings up several questions...

Am I correct in assuming the two sets of shims for both end caps should be the same thickness?

If so how do you know how much clearance to start with, when setting the four sets of shims in place? Iam anticipating laying in equal thicknesses of shims and going nuts taking out thousands on all four positions...

Also, what is the rule of thumb for shimming under the bearing material itself, versus shimming the end cap???

Finally I've heard people say the Dalton bearings were not meant to have actual contact with the spindle - they 'float' on a film of oil, hence .001" clearance is fine. whereas the South Bend bearings have actual contact. Can anyone clarify this?

Thanks much!

Glenn

 

[Kernbigo]

All plain bearings float on a film of oil, last resort shim under the bearing, shim under the cap, one at a time tell you end with .001 lift, not the same on each one, just what you need to end up with .001 lift

 

[Wreck™Wreck]

Bolt the internal journals together without the spindle in place and measure using a bore gauge then measure the external spindle journals, the difference will be the clearance, if unacceptable remove or add shims as needed, Do not however make it tight, as you mentioned a liquid film is formed by the oil and this requires a certain amount of clearance, you do have several .001's to work with depending on spindle size of course.
Years ago I remember using an automotive product called PlastiGage, small pieces of round plastic that were placed in the bearing journals and assembled, after disassembly the gauge was then held against a supplied paper graph which gave the clearance value via the width of the flattened gauge. I found this method a bit crude myself.

Lo and behold, they are still in business in the automotive aftermarket.
http://www.plastigaugeusa.com/how.html

 

[coffmajt]

Bolt the internal journals together without the spindle in place and measure using a bore gauge then measure the external spindle journals, the difference will be the clearance, if unacceptable remove or add shims as needed, Do not however make it tight, as you mentioned a liquid film is formed by the oil and this requires a certain amount of clearance, you do have several .001's to work with depending on spindle size of course.
Years ago I remember using an automotive product called PlastiGage, small pieces of round plastic that were placed in the bearing journals and assembled, after disassembly the gauge was then held against a supplied paper graph which gave the clearance value via the width of the flattened gauge. I found this method a bit crude myself.

Lo and behold, they are still in business in the automotive aftermarket.
http://www.plastigaugeusa.com/how.html

On my South Bend I mount a dial indicator on top of the bearing housing with the stem as close to the spindle as I can get it. I stick a 3/4 inch steel rod into the spindle about 6 inches deep and then lift up on the rod and watch the dial indicator for vertical movement. Anything more than .001 and I adjust the shims on the front bearing. Same technique works on the rear bearing == Jack

 

[Micke S]

The general rule for glide bearing play is 0.001 inch play per 1 inch axle diameter. This can be difficult to achieve on a worn lathe since the bearings are usually out of round. When I renovated an old lathe I used the same method as for renovating con rods; milled the housing and bearing contact surfaces and honed the bearings.

 

[Wreck™Wreck]

On my South Bend I mount a dial indicator on top of the bearing housing with the stem as close to the spindle as I can get it. I stick a 3/4 inch steel rod into the spindle about 6 inches deep and then lift up on the rod and watch the dial indicator for vertical movement. Anything more than .001 and I adjust the shims on the front bearing. Same technique works on the rear bearing == Jack

You can not easily do this when it is running and the thin film in the bearings is dynamic not static. As an experiment put a large piece of stock in a chuck and turn a clean band on it wide enough for an indicator. Place the indicator there and run the spindle under power so there should be very little run out as you have just turned the band in place. Use a piece of lumber with one end placed on the ways and the center on the spinning part and pry upwards and then note the indicator reading this will give you the axial run out when the spindle is in motion and under moderate load, I believe that you may see some surprising results.

 

[Glenn Brooks]

Spent the last several days adjusting sums and judiciously bluing and scraping the rear bearings. I found the bearings and spindle were elongated, out of round a few thou, on both ends. So not a simple process to just shim under the caps. Chuck end of the spindle now is a bit tight, when turning by hand, but has .001 play. If I shim more, the spindle moves freely but exhibits .008" vertical play. Maddening going back and forth. I've hit .001" a couple of times, but when I Added a few thou to the shims to free up the spindle a bit, find the vertical movement blows back out to .008-.010.

Tomorrow I think I will dykum blue the front bearings and see where the high points are then maybe scrape them down a bit and see if I can't get a better fit, with more free turning spindle. The prior owner poured new bearings on the front side of the spindle. So they look pretty good physically, just don't mate up well with the old spindle wear.... My new, old (1929) SB 9a spindle spins like a top- two to three turns - with no excess vertical movement - it's virtually new, still with scraping marks all along the bed - so trying to get close to that is my standard. Probably asking to much from the old Dalton 100year old lathe, without grinding the spindle true and honing the bearings. Don't want to get into chasing the bearings to fit a woren, tapered spindle, when I can eventually grind the spindle on my OD grinder - after I get it working, and become a little more proficient.

Alternately, am thinking about letting the machine wear itself in, with the vertical play shimmed to .001" .

Any thoughts on my best approach here???

Thanks much
Glenn

 

[dturkcars]

Spent the last several days adjusting sums and judiciously bluing and scraping the rear bearings. I found the bearings and spindle were elongated, out of round a few thou, on both ends. So not a simple process to just shim under the caps. Chuck end of the spindle now is a bit tight, when turning by hand, but has .001 play. If I shim more, the spindle moves freely but exhibits .008" vertical play. Maddening going back and forth. I've hit .001" a couple of times, but when I Added a few thou to the shims to free up the spindle a bit, find the vertical movement blows back out to .008-.010.

Tomorrow I think I will dykum blue the front bearings and see where the high points are then maybe scrape them down a bit and see if I can't get a better fit, with more free turning spindle. The prior owner poured new bearings on the front side of the spindle. So they look pretty good physically, just don't mate up well with the old spindle wear.... My new, old (1929) SB 9a spindle spins like a top- two to three turns - with no excess vertical movement - it's virtually new, still with scraping marks all along the bed - so trying to get close to that is my standard. Probably asking to much from the old Dalton 100year old lathe, without grinding the spindle true and honing the bearings. Don't want to get into chasing the bearings to fit a woren, tapered spindle, when I can eventually grind the spindle on my OD grinder - after I get it working, and become a little more proficient.

Alternately, am thinking about letting the machine wear itself in, with the vertical play shimmed to .001" .

Any thoughts on my best approach here???

Thanks much
Glenn

just finishing up a restoration of my lot 5 Dalton lathe. It's in very good condition overall, but has some slop in the headstock bearings. In taking it apart, I think I lost one of the shims from under the bearing cap at the chuck, hence the spindle 'clinks' a bit when I pull it vertically up and down. The bearings are split, so one upper and one lower front and back.

I will be putting a dial indicator on the spindle to measure movement, probably tomorrow.

So it brings up several questions...

Am I correct in assuming the two sets of shims for both end caps should be the same thickness?

If so how do you know how much clearance to start with, when setting the four sets of shims in place? Iam anticipating laying in equal thicknesses of shims and going nuts taking out thousands on all four positions...

Also, what is the rule of thumb for shimming under the bearing material itself, versus shimming the end cap???

Finally I've heard people say the Dalton bearings were not meant to have actual contact with the spindle - they 'float' on a film of oil, hence .001" clearance is fine. whereas the South Bend bearings have actual contact. Can anyone clarify this?

Thanks much!

Glenn

Hi Glen

Took your suggestion and joined the group. I see your in Woodinville Washington. If you get down to the Portland area stop by Turk Mfg. in Hillsboro and take a look at the Dalton collection I have on display there.

As to your spindle bearings I have restored many of the Dalton plain bearings back to less than a .001 clearance but as you have found scraping is required. If you shim the bearings you must put a full piece of shim in the head stock casting. What I mean by this is you need a piece of shim stock that covers all of the bearing seat in the casting. When you force the bearing down into the shim you will not only raise the bearing but you will also claps in the sides of the bearing and you will find that your spindle now does not drop down into the bearing. So now we start scraping the sides of the bearings and I do mean both of them. First off you really need to see if the spindle is sitting parallel to the bed ways. I do this by using a test bar I have that fits the #3 spindle taper and an indicator in the tool post. By running the saddle back and forth you get an idea of how much the spindle is drooping down. If it is you will need to add more shim to the front bearing than the rear. With a little practice you will find that you can bring the spindle back up to height as well as parallel to the bed. The tail stock will have to be dealt with later. The reason for the full shim in the head stock castings is as you have found out the bearings are no longer round and the drag or pressure exerted by the belt driving the spindle will wear the bearings on the back side as well as being worn up and down. I have been successful in reconditioning quite a number of old plain bearing lathes using these techniques.

Dennis Turk

 

[Glenn Brooks]

Hi Dennis, thanks very much for your description of shimming the headstock.

One question: do you usually shim under the top bearing or the bottom headstock bearing? Perhaps the right answer is the test bar will tell you if the spindle needs to go up or down.

I will start making up a spindle taper test bar to true up the alignment. When I bought the machine the headstock and tailstock centers meet very close to center, but at the time I did not put a dial indicator on them. As I've gone this far trying to true things up, might as well shoot for like new condition, if I can...

Also I think I will put the spindle on my OD grinder and take the irregularities out of the bearing surfaces before doing any radical work of the bearings. No sense in fitting the bearings to abnormal wear on the spindle - although it isn't to bad overall.

Yes, would enjoy visiting your shop in Oregon and seeing your collection of Daltons. I have certainly admired the photos of your restored lathes. We will be making a trip to Train Mountain this summer, so will plan on making an appointment to stop by on the way down.

Thanks again for your assistance!

Regards
Glenn

 

[dturkcars]

Hi Dennis, thanks very much for your description of shimming the headstock.

One question: do you usually shim under the top bearing or the bottom headstock bearing? Perhaps the right answer is the test bar will tell you if the spindle needs to go up or down.

I will start making up a spindle taper test bar to true up the alignment. When I bought the machine the headstock and tailstock centers meet very close to center, but at the time I did not put a dial indicator on them. As I've gone this far trying to true things up, might as well shoot for like new condition, if I can...

Also I think I will put the spindle on my OD grinder and take the irregularities out of the bearing surfaces before doing any radical work of the bearings. No sense in fitting the bearings to abnormal wear on the spindle - although it isn't to bad overall.

Yes, would enjoy visiting your shop in Oregon and seeing your collection of Daltons. I have certainly admired the photos of your restored lathes. We will be making a trip to Train Mountain this summer, so will plan on making an appointment to stop by on the way down.

Thanks again for your assistance!

Regards
Glenn

Hi Glen

Forgot to let you know this. The Lot 5 Dalton was introduced in 1922. All small lathes of the 7 1/4 inch swing were Lot 4 machines from early 1914 up to the introduction of the Lot 5 though the Lot 4 was continually built up to the end of production in 1929.
Dennis